CH 232 Midterm 2 W20

Week 5 Learning Outcomes

100

This is the definition of a dynamic equilibrium. 

What does it mean when a reaction is going both ways without any discernible change?

200

If you heat up an exothermic reaction, this will happen according to Le Chatlier's principle. 

Why did the reaction shift left towards reactants?

*In an exothermic reaction, heat is a product. 

300

To determine if a concentration is at equilibrium, you will calculate this. 

What is the equilibrium quotient, Q?

400

This decreases due to the common ion effect. 

Bonus for Double Jeopardy:

How is this explained by Le Chatlier's Principle?

What is molar solubility?

Bonus: 

You are technically increasing the concentration of one of the products. According to Le Chatlier's principle this will cause a leftward shift, meaning less solid can dissolve in solution, therefore decreasing molar solubility. 

500

Find K for 2N₂O(g) + 3O₂(g) <-> 2N₂O₄(g) using the following:

1) 2N₂(g) + O₂(g) <-> 2N₂O(g) K₁=1.2x10^-35

2) N₂O₄(g) <-> 2NO₂(g)            K₂=4.6x10^-3

3) 1/2N₂(g) + O₂(g) <-> NO₂(g) K₃=4.1x10^-9

K=1.1x10⁶

Week 6 Learning Outcomes

100

These are the 6 strong bases. 

What are LiOH, KOH, NaOH, Ca(OH)₂, Sr(OH)₂, and Ba(OH)₂?

200

What is the difference between the Arrhenius definitions for acids and bases and the Bronsted-Lowry definitions?

Does not need to be in the form of a question

Arrhenius bases physically donate an OH^- to solution. Bronsted-Lowry bases accept hydrogens.

300

Ka and Kb describe two different reactions, not reverse reactions. 

(What does this mean in terms of their relationship)

Why aren't Ka and Kb reverse reactions of each other?

*Reason we must use use Kw for the conversion

400

How does percent ionization explain why we don't use ICE tables for strong acids/bases?

Does not need to be in the form of a question

Since strong acids and bases ionize pretty much 100%, this means there is no equilibrium for and ICE to describe. The reaction just goes to completion.

500

Convert this pH to pOH using the Kw method. 

pH=4.1

pOH=9.9

Week 7/8 Learning Outcomes

100

Arrange the following in terms of increasing acidic strength:

ClCH₂CH₂CH₂COOH, CH₂CH₂CHClCOOH, 

CH₂CH₂CHBrCOOH, CH₂CH₂CH₂COOH

CH₂CH₂CH₂COOH<ClCH₂CH₂CH₂COOH<

CH₂CH₂CHBrCOOH<CH₂CH₂CHClCOOH

200

For a triprotic acid Ka₁ is expected to be the biggest followed by Ka₂ and Ka₃. Which Ka do you expect the biggest Kb to be inversely proportional?

Since, Ka₃ is the smallest, that means this step's Kb is the biggest.

300

Delineate the successive deprotonation steps for oxalic acid: H₂C₂O₄.

Does not need to be in the form of the question. 

1. H₂C₂O₄(aq) + H₂O(l) <-> HC₂O₄^-(aq) + H₃O⁺(aq)

2. HC₂O₄^-(aq) + H₂O(l) <-> C₂O₄^2-(aq) + H₃O⁺(aq)

400

Will the following be more soluble in an acid solution or a basic solution?

BeCl₂
Does not need to be in the form of a question

In a basic solution. 

*Be²⁺ is a week acid with a weak conjugate base. 

500

Draw and label the titration curve of a diprotic base.